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<H1 class="no-header">curs_touch 3x</H1>
<PRE>
<STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>                                                  <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>




</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
       <STRONG>touchwin</STRONG>, <STRONG>touchline</STRONG>, <STRONG>untouchwin</STRONG>, <STRONG>wtouchln</STRONG>, <STRONG>is_linetouched</STRONG>,
       <STRONG>is_wintouched</STRONG> - <STRONG>curses</STRONG> refresh control routines


</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
       <STRONG>#include</STRONG> <STRONG>&lt;curses.h&gt;</STRONG>
       <STRONG>int</STRONG> <STRONG>touchwin(WINDOW</STRONG> <STRONG>*win);</STRONG>
       <STRONG>int</STRONG> <STRONG>touchline(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>start,</STRONG> <STRONG>int</STRONG> <STRONG>count);</STRONG>
       <STRONG>int</STRONG> <STRONG>untouchwin(WINDOW</STRONG> <STRONG>*win);</STRONG>
       <STRONG>int</STRONG> <STRONG>wtouchln(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>n,</STRONG> <STRONG>int</STRONG> <STRONG>changed);</STRONG>
       <STRONG>bool</STRONG> <STRONG>is_linetouched(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>line);</STRONG>
       <STRONG>bool</STRONG> <STRONG>is_wintouched(WINDOW</STRONG> <STRONG>*win);</STRONG>


</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
       The <STRONG>touchwin</STRONG> and <STRONG>touchline</STRONG> routines throw away all optimization  infor-
       mation about which parts of the window have been touched, by pretending
       that the entire window has been drawn on.  This is sometimes  necessary
       when  using  overlapping  windows, since a change to one window affects
       the other window, but the records of which lines have been  changed  in
       the other window do not reflect the change.  The routine <STRONG>touchline</STRONG> only
       pretends that <EM>count</EM> lines have been changed, beginning with line <EM>start</EM>.

       The <STRONG>untouchwin</STRONG> routine marks all lines in the window as unchanged since
       the last call to <STRONG>wrefresh</STRONG>.

       The  <STRONG>wtouchln</STRONG>  routine makes <EM>n</EM> lines in the window, starting at line <EM>y</EM>,
       look as if they have (<EM>changed</EM><STRONG>=1</STRONG>) or have not (<EM>changed</EM><STRONG>=0</STRONG>)  been  changed
       since the last call to <STRONG>wrefresh</STRONG>.

       The <STRONG>is_linetouched</STRONG> and <STRONG>is_wintouched</STRONG> routines return <STRONG>TRUE</STRONG> if the speci-
       fied line/window was modified since the last call to  <STRONG>wrefresh</STRONG>;  other-
       wise  they  return  <STRONG>FALSE</STRONG>.   In addition, <STRONG>is_linetouched</STRONG> returns <STRONG>ERR</STRONG> if
       <EM>line</EM> is not valid for the given window.


</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
       All routines return the integer <STRONG>ERR</STRONG> upon failure and an  integer  value
       other  than  <STRONG>ERR</STRONG>  upon successful completion, unless otherwise noted in
       the preceding routine descriptions.

       X/Open does not define any error conditions.  In this implementation

          <STRONG>is_linetouched</STRONG>
               returns an error if the window pointer is null, or if the  line
               number is outside the window.

               The constant <STRONG>ERR</STRONG> is distinct from <STRONG>TRUE</STRONG> and <STRONG>FALSE</STRONG>, which are the
               normal return values of this function.   Because  the  function
               returns a <STRONG>bool</STRONG>, returning <STRONG>ERR</STRONG> (which is neither <STRONG>TRUE</STRONG> nor <STRONG>FALSE</STRONG>)
               may not be supported by the compiler.

               To provide error-checking and also match  the  X/Open  function
               prototype, the <STRONG>ERR</STRONG> is provided by a macro named <STRONG>is_linetouched</STRONG>.
               The actual function returns <STRONG>FALSE</STRONG> when it detects an error.

          <STRONG>wtouchln</STRONG>
               returns an error if the window pointer is null, or if the  line
               number is outside the window.


</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
       These  functions  were  introduced  by SVr4.  The Solaris curses header
       file, for instance, defines both an actual function and macro for each.
       The  macros  give the same result as the actual functions.  SVr4 curses
       does not check the window parameter <EM>win</EM> to ensure that it is not  <STRONG>NULL</STRONG>;
       otherwise this implementation behaves the same as SVr4.

       The XSI Curses standard, Issue 4 describes these functions, but defines
       no error conditions.


</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
       All of these routines except <STRONG>wtouchln</STRONG> may be macros.


</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
       <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>.



                                                                <STRONG><A HREF="curs_touch.3x.html">curs_touch(3x)</A></STRONG>
</PRE>
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<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
<li><a href="#h2-NOTES">NOTES</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
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